Backport of jsr 166: Java class library technical principles detailed explanation
JSR 166 Backward transplant: detailed explanation of Java class library technical principles
Abstract: JSR 166 is part of the Java specification request, which aims to bring a set of highly efficient and scalable concurrent programming libraries to the Java platform.This article will explain the principles of JSR 166's back transplantation and Java -class library technology in detail.We will also provide Java code examples to help you better understand these concepts.
introduction:
With the rapid development of computer hardware technology, modern applications need to make full use of the advantages of multi -core processors and concurrent execution.However, concurrent programming is not easy, often accompanied by a series of problems that plague developers, such as competitive conditions and dead locks.JSR 166's back transplantation aims to provide developers with high -efficiency tools and class libraries for concurrent programming to help them deal with these problems more easily.
The concept of back transplantation:
Back transplantation refers to transplanting a certain technology from one platform to another.In this case, we transplanted the JSR 166 concurrent programming libraries from Java SE 5.0 and higher versions into the old version of Java (such as Java SE 1.4 and lower versions).In this way, developers can still make full use of the benefits of concurrent programming without upgrading the Java version.
Migration compatibility:
When the JSR 166 is transplanted, these libraries need to be compatible with the target Java version.This means that we need to use some techniques and change to adapt to some key features and functions that are missing in the old version.A common method is to use the Java reflection mechanism to simulate new features, thereby making the behavior of the original library like a new version.
Steps to transplant JSR 166 to the old version of Java:
The following are the general steps that transplant the JSR 166 to the old version of Java:
1. First, determine the target Java version to understand its restrictions and lack of functions.
2. Analysis of the class library that needs to be migrated, divided them into core libraries and additional libraries.
3. Use the Java reflection mechanism to create appropriate packaging categories to achieve new features.
4. Create a adapter class for the old version of Java to support the new concurrent class and functions.
5. Strict testing and performance assessment to ensure that the function and performance of the class library of the transplantation is similar to the original version.
Java code example:
Below is an example of Java code that uses JSR 166 concurrent libraries:
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class ConcurrencyExample {
public static void main(String[] args) {
ExecutorService executorService = Executors.newFixedThreadPool(5);
Future<String> future = executorService.submit(() -> {
// Execute some time -consuming operations
Return "result";
});
try {
String result = future.get();
System.out.println ("Operation Result:" + Result);
} catch (Exception e) {
e.printStackTrace();
}
executorService.shutdown();
}
}
In the above example, we use the ExecutorService and Future in the concurrent library of the JSR 166 to perform a task and get its results.These classes and interfaces make concurrent programming easier and reliable.
in conclusion:
By transplantation for JSR 166, we can use the advantages of concurrent programming in the old version of Java without upgrading to a newer Java version.This enables developers to develop multi -threaded applications more easily and better use the advantages of modern hardware.I hope this article can help you better understand the principles of the JSR 166's back transplantation and Java library technology.
